244< MR. S. LE M. MOORE'S STUDIES 



A Search for some other Substances reacting like Proteids. 



Of non-proteids, the only body hitherto discovered which will 

 give all ordinary proteid reactions is, according to Krasser*, 

 tyrosin. Hence, by the process of exclusion, we may dismiss 

 other substances yielding one or more but not all of these re- 

 actions, for it is quite unnecessary to suppose that one reaction is 

 due to one substance, and another to a second, and so on. How- 

 ever, in order to leave no stone unturned, resort was had to the 

 method already applied by the author to Ballia stoppers. This 

 is, to select a given reaction, and place the tissues to be experi- 

 mented with in fluids which act as solvents of the substances yield- 

 ing that reaction. Thus, of the bodies giving Millon's reaction, 

 supposing them to exist as such in the cell-wall and not to form 

 insoluble compounds therein, w r e know that : 



I. Alcohol and Ether should dissolve out Nitrobenzole, 

 Phenol, Thymol, and Naphthol. 

 II. Acid and Alkaline solutions should dissolve out Tyrosin. 

 III. Water should dissolve out Vanillin. 



And this treatment leaves only the aromatic oxy-acids un- 

 accounted for, since preliminary examination showed, from the 

 absence of reddening on addition of Hydrochloric Acid, that 

 Phloroglucin could not be the substance sought for. 



The results of these experiments are here appended. 



I. Sections kept in absolute alcohol for three weeks. 

 Fig (M). Xylem faint reaction — none elsewhere. 



(X). Fairly good reaction in xylem — hard bast not seen. 

 (R), Good reaction in the way already indicated. 

 Arundo Phragmites (M). Normal reaction. 



(X). Ditto. 

 (E). Ditto. 

 JRosa canina (M). Failed. 



(X). Good reaction in tissues already indicated. 



(E). Ditto. 

 Ash (M). Failed. 



(X). Faint reaction in xylem: good in hard bast. 



(E). Normal reaction. 



* See Krasser's list on p. 523 of the Author's first memoir on callus, in Journ. 

 Linn. Soc, Bot. xxvii. 



